For some years, magnetic materials have been known based on substance systems which contain a rare earth metal and a transition metal and are outstanding for their high coercive field strength H.sub.ci and high energy products (B*H).sub.max. Important representatives are Co--Sm binary substance systems and Nd--Fe--B ternary substance systems. Their hard magnetic properties are due to intermetallic compounds with a high magnetic anisotropy and a high structure development in the respective materials. The production of these magnetic materials can be effected, e.g., by sintering powders of the components of the respective substance system (see, e.g., EP-A-0134304). Another possibility is to produce corresponding magnetic materials by means of a so-called rapid solidification (quenching) technology (see, e.g., EP-A-0284832).
Sm--Fe--Ti ternary magnetic materials are also being discussed (see, "J.Appl.Phys.", Vol. 64, No. 10, 1988, pages 5720--5722). Recently, the existence of Sm.sub.2 Fe.sub.17 N.sub.x as magnetic material has become known. This material has the known Th.sub.2 Zn.sub.17 crystal structure, and its intrinsic properties are clearly better than those of Nd.sub.2 Fe.sub.14 B. Thus, for example, the anisotropy field at room temperature is about 20 T, the Curie temperature about 470.degree. C., and the saturation magnetization about 1.54 T. For the production of Sm.sub.2 Fe.sub.17 N.sub.x, the melting of Sm.sub.2 Fe.sub.17 as the starting material is known. The preliminary product thus obtained is then heated in a N.sub.2 or NH.sub.3 atmosphere, with the desired hard magnetic phase forming by inclusion of up to 2.7N atoms per formula unit into the lattice structure of the preliminary product. Furthermore, by nitiriding the Sm.sub.2 Fe.sub.17 preliminary product, a uniaxial magnetic anisotropy of the hard magnetic phase can be obtained. (See paper read by J. M. D. Coey at the convention of the "Nato Advanced Study Institute on the Science and Technology of Nanostructured Magnetic Materials", Jun. 25 to Jul. 7, 1990, Heraklion, Crete, Greece).